Aim. The use of constrained cups is one of the many existing options for the treatment of the dislocating total hip arthroplasty (THA). The scientific literature reports good results and severe failures of this kind of implants. The aim of this study was to evaluate, at short term, a group of constrained cups.Methods. Thirty constrained cups implanted from 1999 to 2006 have been clinically and functionally studied.Results. Twelve patients have been lost at follow-up and 3 died. Thirteen patients of the 15 evaluated had good clinical results; none had dislocation or implant’s failure.Conclusions. The constrained acetabular component is effective in the treatment of the dislocating THA, and also can be used in particular first implants. The cup of this study allows some tolerance in the locking system, thus reducing the stress at bone-cement-implant level and the related mechanical failure.